<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
  
  </style>
</head>

<body>
  <div id="app">
    <h1>Tab 切换</h1>
    <div class="title">
      <b v-for="(v, i) in tabs" 
        v-bind:class="{active: i === activeIndex}"
        v-on:click="activeIndex = i"
      >{{ v.title }}</b>
    </div>

    <ul>
      <li 
        v-for="(v, i) in tabs[activeIndex].heros"
      >{{ v }}</li>
    </ul>
  </div>
</body>

</html>